Various exercise devices have been used to increase the strength and range of motion of the muscles and tendons in the hands and forearms. One type of device is used to simultaneously exercise both hands. Such devices typically include a pair of handles coupled together by an elastic tensioning member, with the user repeatedly pulling the handles apart and then allowing the handles move back together. This type of exercising device relies upon the individual to utilize the appropriate muscles when operating the device. However, the individual may have a tendency to use other muscles such as those in the upper arms, back and chest area to provide assistance during the exercises, particularly when the individual begins to tire. If other muscles are used, the exercises will work the stronger muscles while having a minimal effect on the target muscles and tendons of the hands and forearms. When the exercises are used for rehabilitation purposes, maximizing the effect of the exercises on the muscles in the hands and forearms is of particular importance. An exercise apparatus which isolates the muscles in the hand and forearm from the assistance of other muscle groups is desirable.
For an exercise device to be effective, the device must apply the appropriate amount of resistance to the muscles during the exercises. The two-hand exercise devices typically apply a fixed amount of resistance, requiting the individual to utilize a different device if a greater or lesser amount of resistance is required. An exercising apparatus in which the individual may vary the amount of resistance applied during the exercises is desirable.
Other exercise devices may be used to exercise one hand by grasping a pair of spaced handles in one hand and repeatedly closing the hand to move the handles together. U.S. Pat. Nos. 4,226,412 and 4,553,746 disclose examples of one-hand exercise devices in which the resistance is provided by springs. The resistance provided with the device shown in U.S. Pat. No. 4,553,746 may be varied somewhat by adjusting the amount the springs are compressed. However, the disclosed devices must be disassembled and the springs replaced if the individual wishes to significantly change the resistance. U.S. Pat. Nos. 3,570,849 and 5,125,878 disclose exercise devices for one hand in which the resistance may be adjusted by easily adding or removing tensioning members. With the device shown in U.S. Pat. No. 5,125,878, the distance initially separating the spaced handles may also be adjusted.
An exercise device for one or both hands in which the proper resistance may be provided for each application is desirable. Similarly, an exercise device in which the resistance may be adjusted without altering the device is desirable. An exercise device in which the resistance may be varied during each exercise stroke is also desirable.